Completion status
This method returns if the operation has completed.
A SELECT
query is completed if all rows have been fetched.
A data manipulation statement is always completed.
dbHasCompleted(res, ...)
res |
An object inheriting from DBIResult. |
... |
Other arguments passed on to methods. |
dbHasCompleted()
returns a logical scalar.
For a query initiated by dbSendQuery()
with non-empty result set,
dbHasCompleted()
returns FALSE
initially
and TRUE
after calling dbFetch()
without limit.
For a query initiated by dbSendStatement()
,
dbHasCompleted()
always returns TRUE
.
Attempting to query completion status for a result set cleared with
dbClearResult()
gives an error.
The completion status for a query is only guaranteed to be set to
FALSE
after attempting to fetch past the end of the entire result.
Therefore, for a query with an empty result set,
the initial return value is unspecified,
but the result value is TRUE
after trying to fetch only one row.
Similarly, for a query with a result set of length n,
the return value is unspecified after fetching n rows,
but the result value is TRUE
after trying to fetch only one more
row.
Other DBIResult generics:
DBIResult-class
,
dbBind()
,
dbClearResult()
,
dbColumnInfo()
,
dbFetch()
,
dbGetInfo()
,
dbGetRowCount()
,
dbGetRowsAffected()
,
dbGetStatement()
,
dbIsReadOnly()
,
dbIsValid()
,
dbQuoteIdentifier()
,
dbQuoteLiteral()
,
dbQuoteString()
,
dbUnquoteIdentifier()
con <- dbConnect(RSQLite::SQLite(), ":memory:") dbWriteTable(con, "mtcars", mtcars) rs <- dbSendQuery(con, "SELECT * FROM mtcars") dbHasCompleted(rs) ret1 <- dbFetch(rs, 10) dbHasCompleted(rs) ret2 <- dbFetch(rs) dbHasCompleted(rs) dbClearResult(rs) dbDisconnect(con)
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